'\" et
.TH WCSTOK "3P" 2017 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\"
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.\"
.SH NAME
wcstok
\(em split a wide-character string into tokens
.SH SYNOPSIS
.LP
.nf
#include <wchar.h>
.P
wchar_t *wcstok(wchar_t *restrict \fIws1\fP, const wchar_t *restrict \fIws2\fP,
    wchar_t **restrict \fIptr\fP);
.fi
.SH DESCRIPTION
The functionality described on this reference page is aligned with the
ISO\ C standard. Any conflict between the requirements described here and the
ISO\ C standard is unintentional. This volume of POSIX.1\(hy2017 defers to the ISO\ C standard.
.P
A sequence of calls to
\fIwcstok\fR()
shall break the wide-character string pointed to by
.IR ws1
into a sequence of tokens, each of which shall be delimited by a
wide-character code from the wide-character string pointed to by
.IR ws2 .
The
.IR ptr
argument points to a caller-provided
.BR wchar_t
pointer into which the
\fIwcstok\fR()
function shall store information necessary for it to continue
scanning the same wide-character string.
.P
The first call in the sequence has
.IR ws1
as its first argument, and is followed by calls with a null pointer as
their first argument. The separator string pointed to by
.IR ws2
may be different from call to call.
.P
The first call in the sequence shall search the wide-character string
pointed to by
.IR ws1
for the first wide-character code that is
.IR not
contained in the current separator string pointed to by
.IR ws2 .
If no such wide-character code is found, then there are no tokens in
the wide-character string pointed to by
.IR ws1
and
\fIwcstok\fR()
shall return a null pointer. If such a wide-character code is found,
it shall be the start of the first token.
.P
The
\fIwcstok\fR()
function shall then search from there for a wide-character code that
.IR is
contained in the current separator string. If no such wide-character
code is found, the current token extends to the end of the
wide-character string pointed to by
.IR ws1 ,
and subsequent searches for a token shall return a null pointer. If
such a wide-character code is found, it shall be overwritten by a null
wide character, which terminates the current token. The
\fIwcstok\fR()
function shall save a pointer to the following wide-character code,
from which the next search for a token shall start.
.P
Each subsequent call, with a null pointer as the value of the first
argument, shall start searching from the saved pointer and behave as
described above.
.P
The implementation shall behave as if no function calls
\fIwcstok\fR().
.SH "RETURN VALUE"
Upon successful completion, the
\fIwcstok\fR()
function shall return a pointer to the first wide-character code of a
token. Otherwise, if there is no token,
\fIwcstok\fR()
shall return a null pointer.
.SH ERRORS
No errors are defined.
.LP
.IR "The following sections are informative."
.SH EXAMPLES
None.
.SH "APPLICATION USAGE"
None.
.SH RATIONALE
None.
.SH "FUTURE DIRECTIONS"
None.
.SH "SEE ALSO"
The Base Definitions volume of POSIX.1\(hy2017,
.IR "\fB<wchar.h>\fP"
.\"
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1-2017, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 7, 2018 Edition,
Copyright (C) 2018 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group.
In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .
.PP
Any typographical or formatting errors that appear
in this page are most likely
to have been introduced during the conversion of the source files to
man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
